Maybe an ignition switch fault ?

I had an 'interesting' problem one night with my previous Audi when driving home in the dark one night, the dipped lights stopped working . After initial panic I found that the Full beam was still okay and had to drive home on Full beam - good job there were no other cars about. After investigation the next day, this turned out to be a faulty ignition switch. I bought one from Euro Car Parts and fitted it - it wasn't too difficult or expensive.

I'm thinking that your switching on/off the ignition is making it work again temporarily ?

Hope that this helps,
Bob